The use of hearing protective and noise attenuating devices is well known, and various types of devices are available including, but not limited to, ear muffs, semi-aural devices, and earplugs. Earplugs are often preferred for their effectiveness in attenuating sound and for comfort properties provided thereby.
An earplug generally comprises a sound attenuating element which is placed in the ear canal of a wearer to occlude the canal and thus provide a desired sound attenuation. The sound attenuating element is commonly made of a compressible, resilient material such as a foam or a rubber.
The earplug may further include a stem extending from the sound attenuating element. The stem serves as a handle to facilitate general tactile manipulation of the earplug. Furthermore, the stem assists during insertion of the earplug into the earcanal by serving as a means for pushing the sound attenuating element to a sufficient depth within the earcanal. Correspondingly, the stem aids in removal of the earplug by providing a grip by which the earplug may be pulled from the earcanal.
The sound attenuating element and the stem of such earplugs may be formed separately and then fixed together or may be integrally formed together. In the case of the former, a rigid or semi-rigid stem is typically embedded partly or entirely within the resilient sound attenuating element. An adhesive is used to fix the stem to the attenuating element or the attenuating element may be formed directly on the stem so as to bond intimately therewith. In either case, manufacture and assembly can be a complicated, multi-step process, perhaps requiring numerous toolings, etc., and resulting in an overall increased cost of the earplug. Moreover, the stems for these types of earplugs are typically quite rigid so as to sustain being inserted within the sound attenuating element and bonded therein. While this relatively increased rigidity facilitates assembly of this traditional earplug, it detracts from the comfort provided thereby to the user by preventing or limiting the ability of the stem and earplug to conform to the natural curvature of the inner ear.
A conventional earplug having an integrally formed (i.e., one-piece) attenuating element and stem is typically pre-molded of a soft rubber-like material. This material is advantageous due to the comfort properties provided thereby. However, the soft rubber material lacks in rigidity and thus can be less effective for inserting the sounding attenuating element to a desired depth within the ear canal. Attempts at increasing the rigidity of the stem of this type of integrally formed earplug may be unsuccessful due to the corresponding stiffening of the sound attenuating element and hence the loss of comfort properties thereof. Some have attempted to add stiffening elements to the stem of integrally formed, pre-molded earplugs. However, this can be a complex assembly process and can result in an overall more expensive earplug. Moreover, the stiffening element is often too long relative to the axis of the earplug and thus cannot easily traverse the bend in the earcanal when inserted or is too short and thus does not properly serve the intended stiffening function.
Thus, an earplug is desired which includes a soft, comfortable sound attenuating element and a stem attached thereto for handling and inserting the earplug, where the stem is sufficiently rigid to enable insertion of the attenuating element to a desired earcanal depth and yet sufficiently pliable to remain comfortable within the ear and to allow the earplug to conform to the natural contours of the earcanal, and where the earplug is capable of being readily manufactured and assembled at a reasonable cost.